Blocked oven thermostat byepass.
This has to be tested for when commissioning an oven. Get it up to temperature and then turn down control knob, flam should sit down but not extinguish, if it extinguishes it's failed is category ID.
This is why you can't do landlord checks economically, to test properly takes time.
to check flame failure device you turn off oven until flame extinguished, and then keep trying it to see if full gas flow gets through, within the time given in corgi manual gas must stop coming through. Listening for the click after you have turned off isn't really correct, you should actually prove the gas doesn't come through fully after the click..
I don't see the problem giving the guy the answer.
The bypass is a little hole which gets blocked, a blocked one could be fatal, it is ID and needs to be understood by anyone qualified to say if applaince is safe or not.
Most gas leaks are around ovens and hobs.
My advise to OP is don't have anything to do with kitchens whatsoever, that's where you find too many cowboys. Best to stay clear of them altogether.
From a business point ov fiew kitchen fitters and their customers are bad for business. They think your job is easy, they will want you up and down to that job more often than Janice Battersbies knickers.
You want to price yourself out of that market.
